1. Field
The following description relates to a sheet for shielding against electromagnetic waves and a wireless power charging device.
2. Description of Related Art
As weights of various electronic apparatuses are decreased due to miniaturization and lightness of the electronic apparatuses, a non-contact charging method or wireless charging method that charges a battery using magnetic coupling without electrical contact has been developed.
The wireless charging method, which is a method to charge a battery using electromagnetic induction, is a method that charges a battery by converting current generated by inductive coupling between a primary coil (a transmitter coil) provided in a charger (a wireless power transmission device) and a secondary coil (a receiver coil) provided in an object to be charged (a wireless power reception device) into energy.
In this case, a sheet to shield against electromagnetic waves may be disposed between the receiver coil and the battery. The sheet for shielding against electromagnetic waves serves to block a magnetic field generated at the receiver coil from reaching the battery and to efficiently transmit electromagnetic waves generated from the wireless power transmission device to the wireless power reception device.
In a case of wireless charging using the sheet to shield against electromagnetic waves as described above, while power of several to several tens of watts continuously moves, loss of a material and a circuit may occur, and thus a large amount of heat may be generated. Therefore, research into a method of effectively discharging heat generated in the sheet for shielding against electromagnetic waves or the surroundings thereof has been actively conducted.